nanovna-saver/test/test_touchstone.py

#  NanoVNASaver
#
#  A python program to view and export Touchstone data from a NanoVNA
#  Copyright (C) 2019, 2020  Rune B. Broberg
#  Copyright (C) 2020 NanoVNA-Saver Authors
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <https://www.gnu.org/licenses/>.
import unittest
import logging
import os

# Import targets to be tested
from NanoVNASaver.Touchstone import Options, Touchstone
from NanoVNASaver.RFTools import Datapoint

class TestTouchstoneOptions(unittest.TestCase):
    def setUp(self):
        self.opts = Options()

    def test_defaults(self):
        self.assertEqual(self.opts.unit, "ghz")
        self.assertEqual(self.opts.parameter, "s")
        self.assertEqual(self.opts.format, "ma")
        self.assertEqual(self.opts.resistance, 50)
        self.assertEqual(self.opts.factor, 1000000000)
        self.assertEqual(str(self.opts), "# GHZ S MA R 50")

    def test_parse(self):
        self.assertRaisesRegex(
            TypeError, "Not an option line:",
            self.opts.parse, "")
        self.assertRaisesRegex(
            TypeError, "Not an option line: !",
            self.opts.parse, "!")
        self.assertRaisesRegex(
            TypeError, "Illegal option line: # ILLEGAL",
            self.opts.parse, "# ILLEGAL")
        self.assertRaisesRegex(
            TypeError, "Illegal option line: # GHz mhz",
            self.opts.parse, "# GHz mhz")
        self.opts.parse('# khz')
        self.assertEqual(str(self.opts), "# KHZ S MA R 50")
        self.assertEqual(self.opts.factor, 1000)
        self.opts.parse('# r 123 ri hz y')
        self.assertEqual(str(self.opts), "# HZ Y RI R 123")
        self.assertEqual(self.opts.factor, 1)


class TestTouchstoneTouchstone(unittest.TestCase):

    def test_load(self):
        ts = Touchstone("./test/data/valid.s1p")
        ts.load()
        self.assertEqual(str(ts.opts), "# HZ S RI R 50")
        self.assertEqual(len(ts.s11data), 1010)
        self.assertEqual(len(ts.s21data), 0)
        self.assertEqual(ts.r, 50)

        ts = Touchstone("./test/data/valid.s2p")
        ts.load()
        self.assertEqual(str(ts.opts), "# HZ S RI R 50")
        self.assertEqual(len(ts.s11data), 1020)
        self.assertEqual(len(ts.s21data), 1020)
        self.assertEqual(len(ts.s12data), 1020)
        self.assertEqual(len(ts.s22data), 1020)
        self.assertIn("! Vector Network Analyzer VNA R2", ts.comments)

        ts = Touchstone("./test/data/ma.s2p")
        ts.load()
        self.assertEqual(str(ts.opts), "# MHZ S MA R 50")

        ts = Touchstone("./test/data/db.s2p")
        ts.load()
        self.assertEqual(str(ts.opts), "# HZ S DB R 50")

        ts = Touchstone("./test/data/broken_pair.s2p")
        with self.assertLogs(level=logging.ERROR) as cm:
            ts.load()
        self.assertRegex(cm.output[0], "Data values aren't pairs")

        ts = Touchstone("./test/data/missing_pair.s2p")
        with self.assertLogs(level=logging.ERROR) as cm:
            ts.load()
        self.assertRegex(cm.output[0], "Inconsistent number")

        ts = Touchstone("./test/data/nonexistent.s2p")
        with self.assertLogs(level=logging.ERROR) as cm:
            ts.load()
        self.assertRegex(cm.output[0], "No such file or directory")

    def test_db_conversation(self):
        ts_db = Touchstone("./test/data/attenuator-0643_DB.s2p")
        ts_db.load()
        ts_ri = Touchstone("./test/data/attenuator-0643_RI.s2p")
        ts_ri.load()
        ts_ma = Touchstone("./test/data/attenuator-0643_MA.s2p")
        ts_ma.load()
        self.assertEqual(len(ts_db.s11data), len(ts_ri.s11data))
        for dps_db, dps_ri in zip(ts_db.s11data, ts_ri.s11data):
            self.assertAlmostEqual(dps_db.z, dps_ri.z, places=5)

        self.assertEqual(len(ts_db.s11data), len(ts_ma.s11data))
        for dps_db, dps_ma in zip(ts_db.s11data, ts_ma.s11data):
            self.assertAlmostEqual(dps_db.z, dps_ma.z, places=5)

    def test_load_scikit(self):
        ts = Touchstone("./test/data/scikit_unordered.s2p")
        with self.assertLogs(level=logging.WARNING) as cm:
            ts.load()
        self.assertEqual(cm.output, [
            'WARNING:NanoVNASaver.Touchstone:Non integer resistance value: 50.0',
            'WARNING:NanoVNASaver.Touchstone:Comment after header: !freq ReS11 ImS11 ReS21 ImS21 ReS12 ImS12 ReS22 ImS22',
            'WARNING:NanoVNASaver.Touchstone:Frequency not ascending: 15000000.0 0.849810063 -0.4147357 -0.000306106 0.0041482 0.0 0.0 0.0 0.0',
            'WARNING:NanoVNASaver.Touchstone:Reordering data',
            ])
        self.assertEqual(str(ts.opts), "# HZ S RI R 50")
        self.assertEqual(len(ts.s11data), 101)
        self.assertIn("!freq ReS11 ImS11 ReS21 ImS21 ReS12 ImS12 ReS22 ImS22",
                      ts.comments)

    def test_save(self):
        ts = Touchstone("./test/data/valid.s2p")
        self.assertEqual(ts.saves(), "# HZ S RI R 50\n")
        ts.load()
        lines = ts.saves().splitlines()
        self.assertEqual(len(lines), 1021)
        self.assertEqual(lines[0], "# HZ S RI R 50")
        self.assertEqual(lines[1], '500000 -0.333238 0.000180018')
        self.assertEqual(lines[-1], '900000000 -0.127646 0.31969')
        lines = ts.saves(4).splitlines()
        self.assertEqual(len(lines), 1021)
        self.assertEqual(lines[0], "# HZ S RI R 50")
        self.assertEqual(lines[1], '500000 -0.333238 0.000180018 0.67478 -8.1951e-07 0.67529 -8.20129e-07 -0.333238 0.000308078')
        self.assertEqual(lines[-1], '900000000 -0.127646 0.31969 0.596287 -0.503453 0.599076 -0.50197 -0.122713 0.326965')
        ts.filename = "./test/data/output.s2p"
        ts.save(4)
        os.remove(ts.filename)
        ts.filename = ""
        self.assertRaises(FileNotFoundError, ts.save)

        ts.s11data[0] = Datapoint(100, 0.1, 0.1)
        self.assertRaisesRegex(
            LookupError, "Frequencies of sdata not correlated", ts.saves, 4)